On Fri, 24 Mar 2017 15:01:41 -0700 Andrew Baumann <andrew.baum...@microsoft.com> wrote:
> From: Andrey Shedel <ashe...@microsoft.com> > > The multithreaded TCG implementation exposed deadlocks in the win32 > condition variables: as implemented, qemu_cond_broadcast waited on > receivers, whereas the pthreads API it was intended to emulate does > not. This was causing a deadlock because broadcast was called while > holding the IO lock, as well as all possible waiters blocked on the > same lock. > > This patch replaces all the custom synchronisation code for mutexes > and condition variables with native Windows primitives (SRWlocks and > condition variables) with the same semantics as their POSIX > equivalents. To enable that, it requires a Windows Vista or newer host > OS. > > [AB: edited commit message] > Signed-off-by: Andrew Baumann <andrew.baum...@microsoft.com> > --- > The major implication of this patch is that it drops support for > pre-Vista versions of Windows. However, those OSes are past their end > of life, and other OSS projects have dropped support. e.g.; the last > Cygwin release supporting XP was in Jun 2016. It doesn't seem like a > good tradeoff to invest effort in fixing broken code needed to support > them, so hopefully this isn't too controversial. Just a quick question: I noticed that this breaks builds on an old fc20-based installation I run some mingw cross builds on (getting an undefined reference to `_imp__TryAcquireSRWLockExclusive@4'). I should probably take that as a trigger to update that installation ;), but wanted to confirm that this is expected.
